Dominic Wölki

PhD Student
Lehrstuhl für Endogene Geodynamik (Prof. Dr. Haase)
+499131 85-23387
dominic.woelki@fau.de
Schloßgarten 5
91054 Erlangen

Ophiolites – Insights into mantle melting and subduction zone processes
Subduction zone magmas – Aegean Arc

Summary:

Ophiolites are assemblages of submarine basaltic volcanic rocks, underlain by sheeted dyke complex, gabbroic and ultramafic cumulates, which in turn are underlain by depleted upper mantle peridotites. Ophiolites are generally considered to be fragments of oceanic crust and upper mantle emplaced on land, and potentially give insights into the volcanic structure and mode of formation of the oceanic crust.

The presence of a sheeted dyke complex and the enrichment in fluid-mobile elements in volcanic rocks of the Troodos ophiolite indicates a formation at a spreading centre in the vicinity of a subduction zone. So-called supra-subduction zone ophiolites. Thus, Cyprus provides an exceptional natural laboratory to investigate the influence of both processes. The occurrence of fresh volcanic glass and the use of microanalytical measurement methods allows us to avoid the effects of extensive seafloor alteration processes.

We will carry out major and trace element and Sr-Nd-Pb-Hf isotope measurements of fresh volcanic glasses from different sections to get a “three-dimensional” geochemical model of the extrusive series of the Troodos ophiolite. This dataset will place new constraints on tectonic models for the origin of supra-subduction zone ophiolites.

Methods:

Mineral- and glass composition by electron microprobe analysis, LA-ICP-MS.

Oxygen isotope composition and radiogenic isotopes by Laser-fluorination and MC-ICP-MS.

Publications